Which model BEAM are you using? Is BEAM wired or wireless? What model TV? Is the TV wired or wireless? How is the TV connected to BEAM? What are you playing on the TV when this issue occurs? Is there an error message on the TV?

The Beam is a Sonos Beam Compact Smart Soundbar. It is wireless and connected to the TV’s ARC-port. There is 2 Sonos One (Gen. 2) as surrounds and a Sonos Sub wireless subwoofer.
The TV-signals come from a wireless Apple TV 4K. It is when I use Apple TV on the typical television apps, not when using YouTube. There is no error message, the TV is hang up and the screen is unclear.

Hi @HeddeRolf 

Welcome to the Sonos Community!

I recommend you get in touch with our technical support team, who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

I hope this helps.